These teachings relates generally to method and systems for disturbance rejection in switching power converters and other systems.
An exemplary embodiment, although the president teachings are not limited to any exemplary embodiment, of the switching power converters is a buck regulator. FIG. 1 depicts the conventional feedback control of a buck regulator. The compensator is designed to provide the appropriate duty cycle command in order to achieve regulation of the output voltage around a desired set point. The compensator must be designed to achieve zero steady state error, fast transient response and loop stability. Other exemplary embodiments, these teachings not being limited only to those embodiments, include boost and flyback converters.
In some conventional forms of load feedforward disturbance rejection (for example, the form of feedforward shown in the Linear Technology LTC3401 data sheet), the load feedforward signal is generated by a microprocessor which has knowledge of changes in the load current. In some applications, the predictive signal allows for a reduction in the size of the output capacitors required for a given level of transient performance
There is a need to provide improved method and systems for disturbance rejection in DC-DC converters.
Feedback is inherently limited by stability concerns. Conventional Feedforward architectures are inherently superior if the plant inversion is precise. To address this, most conventional Feedforward architectures are augmented by a feedback architecture to correct for the errors. However, precise plant inversion can be extremely difficult to achieve due to unknown plant parameters, non-linearities, or causality problems (plant delay).
There is a need for method and systems for disturbance rejection in DC-DC converters that do not require apriori knowledge of precise plant inversion.